ANALYSIS OF POWDER FACTOR IN LIMESTONE MINE – A CASE STUDY
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Date
2019-06-24
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MPUT, UDAIPUR
Abstract
In hard rock excavations, drilling and blasting is the cheapest method of rock breaking
and it is widely used. Blasting efficiency depends on many parameters includes
controllable and non controllable. The blasting efficiency assesses in the form of rock
fragmentation, powder factor and blast induced environmental nuisances. Powder
factor is an important parameter used in blast design process. It is ratio between
amount of rock broken and total weight of explosive consumed (tonne/kg or m3/kg).
Higher powder factor produces oversize and lower powder factor resulted into fines.
The favourable size for primary crusher feed will have positive effects on power
factor and cost consumption. An optimum blast is associated with the most efficient
utilization of explosive energy in the rock breaking process. This research work is
carried out to aim analysis and improvisation of powder factor and rock fragmentation
achieved by blasting at JK cement Maliakhera limestone mine, Nimbahera,
Chittorgarh. All blasts were conducted on the same geology and blast parameter. The
variable parameter is quantity of explosive by the use of decking provided between
charge lengths through air deck (wooden spacer)/ solid decking by (drill cutting). To
analyze rock fragmentation WG-FRAGALYST 3.0 software based on digital image
analysis technique was used. Fragmentation characteristics such as fragment size K25,
K50, K98 and uniformity index were calculated by introducing digital images to the
software.
The variable parameter is quantity of explosive by the use of decking provided
between charge lengths. Wooden spacer (Air deck) and drill cutting aggregates were
used to provide deck between charge columns. Powder factor and rock fragmentation
size distribution analysed for all baseline blasts and experimental blasts. In the
analysis, powder factor was improved 7.61% in solid deckand14.34% in air deck
blasting. The obtained mean fragment size K50 and top size K98 decreased for
required maximum crusher feed size is 1.0 m. Though in oversize boulders reduced
19.67% and 37% respectively. Reduction in energy factor 8.77% in case of solid
decking and 12.93% in case of air deck blasting. By decking total charge per hole
reduced and results of rock fragmentation and powder factor were improved
Description
ANALYSIS OF POWDER FACTOR IN LIMESTONE MINE – A CASE STUDY
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Citation
Sukhwal H. And Jain S.C.